I have helped many people over the years with amps VS AVRs--it depends,
My latest person is a self proclaimed "audiophile" and he had verious incorrect theories about amplifiers. He wanted an AVR but to run his favorite ubertastic X series amplfier. No problem! Get thise 100 watt per channel AVR and plug the amp in for your left/right and be done with it. His ubertastic amp had no powerr meters but did have a clip light and put out around 200 watts per channel. He was a happy camper for about a month--then the questions come in. His speakers are a sky high 103 dB efficient fully horn loaded big boxes and he uses VBSS subwoofers. He pondered does he "need" the Uber amp for his L/R for the HT in the living room?
Since electronics is not his thing, he wondered if there was a better way to test it. I ambled over with my Crown XTi amplifier that has power output/clip/limiter lights but has an added feature--adjustable limiter. I plugged in the USB and set the voltage limiter to 30 volts (around 110 watts) and let him play with it for a few weeks. Told him to write down what power level lights peak out at, he has -30dB, -20dB, -10dB and the limiter light will flash at -5dB because it was adjusted down. Told him to go into rockstar mode, play movies at reference and yell more power! when giving the system the screws.
A few weeks go by and I drop by to visit. He removed my amplifier AND his amplifier and was running just the AVR--he had his answer. He told me he blasted it to -10dB (30 watts) and when using speakers rated at 103dB at one watt--he was going well past reference and things became sonicly uncomfortable. He did run my amp to the limiters set at around 110 watts and when his mains were pumping 124dB each it was physically painful. He did all sorts of listening, thought about it then removed my amp. He had friends over for movies, music and jam sessions--they never noticed any change but he did turn the amps on so it looked like they were still hooked up. Weird, his muscian buddies did not notice.
If you understand efficiency and power--you'd laugh at him thinking he needs amplifiers for reference levels--very true. He was happy that he didn't need more power, really happy that his favrite amp can be used to make another sound system
He loves his old amp, his faithful companion for decades and likes the look of the "old iron" so life is good. He hooked it up to some different, low efficiency speakers (around 85dB) and does notice on occassion he will hit the clip light. Strange how his AVR has much higher SPL capability but that is how the game works. For his low efficiency speakers, he NEEDS as much power as he can get and being 4 ohms--I'd advise running high current amplifiers to provide the power pigs some chow.
The right tool for the job applies in audio as well as everything else on the planet--audio is not "special" in any way, shape or form. For me, if an amplifier operates on the cool end of the spectrum, does not clip for my SPL, speaker impedance and thermal capabilities (garage gets HOT so no AVRs out there!) has the features I demand (power output meters/clip lights as I won't purchase amps that don't) all is well. Then it comes down to aesthetics--nothing wrong if the amplifier looks nice. Presently, I have one AVR, two outboard amps and the mighty Class D chip integrated amp at my disposal. My AVR does not require outboard amplfiers because my mains/center is 98dB at one watt and a solid 8 ohms so it runs very cool, no issues with it even at reference levels. My XTi is used to power subwoofers and my other amp sits in the garage powering line arrays. About once a year, time to party so the XTi is removed from the subs and powers the line arrays outside in the heat. No problems, it can tap the limiter light with each drum hit all day in very hot weather as the limiter is set at -2.5dB. Those fans sure kick over in the summer heat! My other amp is passively cooled so not a good idea--wrong rig for the gig.
My buddy never did mention "sound quality" to me--I figured he would of put the XTi against his uber amp--most likely he did! I have no idea what he did with my amp, did he compare it to his then compare them against the AVR amps? Most likely, all part of the fun when playing with a new toy. New toys are better when you don't play with them. I never asked him mainly because I don't care.
I did blind ABX testing with amps and receivers back in the day, learned what I wanted to know and pressed on.
I do find it odd that people will give ONE reason why they need large amplifiers--"because they sound better". Uhhhhh, not in my experience so no gain. At least some people tell me the truth, they like the look of big amps, the feel of stout switches/knobs or feel better if sometime in the future, they need more power they will have it! Nothing wrong with that, I had a 400 watt per channel amp hooked up to some bookshelf speakers in a college dorm. Did not "need" the power, could not use the power and would physically get my butt kicked even if those bookshelf speakers could handle that kind of power!
Once those booshelves went past 100 watts, they would protest with major distortion although the amp had another +6dB in the tank before it would think of clipping. Was I an idiot for having such a powerful amp that I could never use? No, I liked the look of it, the quality components and eventually--I had speakers that could use the power without distortion. I've owned quite a few amplifiers over the years be they car amps, PA amps, consumer amps and now throw in a chip amp. Realistically, for the amplifiers I purchase none of them have an edge for "sound quality" but they all do different things and I never purchased them for sound quality in the first place.
When asked, the only recommendation I have is at the very least--it should have a clip light. Not a hard demand but it does amaze me that some very expensive consumer amps don't have them. I find them critical for proper gain structure in sound systems and find it odd that most of them are gone.
The XTi is very entertaining for the OCD, it has mutliple screens of input/output wave forms, voltages etc. and slap on a tablet and go. Maybe now that Samsung has taken over Harman, they can revive HK and put that feature cooked in for consumer AVRs--it could happen! They own the tech so I'm crossing my fingurs--my AVR won't last for ever.
For Bear, I would rent a Crown XLS1502 for a weekend (pro sound places rent them) hook up two channels and listen for anything a bit crazy with your HTM-8s. Depending on your configuration, how efficient your surrounds are and how close to you they are located--most likely you can let the AVR do the surrounds and let a 3-channel do the hard lifting. The AVR can then use it's power supply to really throw some current at the surrounds so a win all the way around. My next project is building some surrounds at 96dB 1w/1m and a solid 8 ohms (16 ohm tweeter) Overkill? You bet but ya never know when you might inherit a 20 x 40 foot building so.. never know when you will need surrronds capable of 120 dB at one meter.
Shame you on't live near me, I could lend you my XTi and have you play with the adjustable limiter to see what you need.